Many industrial and other processes rely on accurate timing of processes and data flow. For example, steps may need to be taken in a certain sequence or with certain timing, and accurate clock information is critical in such situations. Problems with time synchronization can arise especially when different systems are integrated or operated together and must operate on a common clock. Although it is possible to simply transmit a clock signal from one system to another, this technique leaves the system vulnerable to falling out of synchronization due to a disruption of the line carrying the clock signal or the machine supplying the signal.
An example of integration wherein time synchronization is important is in integrating different control systems together to control a single process or set of processes.